Speaker
Description
We introduce a mechanism by which a misaligned ALP can be dynamically converted into a dark photon in the presence of a background magnetic field. An abundance of non-relativistic ALPs will produce dark photons with momentum of order the inhomogeneities in the background field; therefore a highly homogeneous field will produce non-relativistic dark photons. In the large magnetic field regime, the dark photons exhibit the `gliding' phenomena in which their energy density decays slower than matter. On the other hand, in the smaller field regime, the energy density converts to dark photons during a time in which one would naively assume the field is frozen by Hubble friction, the energy density decays like radiation. Inhomogeneities in the magnetic field decrease the conversion efficiency.
